Tool support for randomized unit testing

There are several problem areas that must be addressed when ap-plying randomization to unit testing. As yet no general, fully au-tomated solution that works for all units has been proposed. We therefore have developed RUTE-J, a Java package intended to help programmers do randomized unit testing in Java. In this paper, we describe RUTE-J and illustrate how it supports the development of per-unit solutions for the problems of randomized unit testing. We report on an experiment in which we applied RUTE-J to the standard Java TreeMap class, measuring the efficiency and effec-tiveness of the technique. We also illustrate the use of randomized testing in experimentation, by adapting RUTE-J so that it gener-ates randomized minimal covering test suites, and measuring the effectiveness of the test suites generated.